A new technique for amplified immunoassay will be developed for measurement of drugs of abuse in saliva specimens. It uses the coagulation cascade with a snake venom activator (Russell's Viper venom factor X activator, RVV-XA) as a labeling enzyme to label antibodies reactive with THC, cocaine/benzoylecgonine, opiates or amphetamines/methamphetamines in an immunochromatography format (ELISA). Coagulation activity is measured using colored microbeads coated with fibrinogen and solid-phase, immobile fibrinogen (enzyme-linked coagulation assay, or ELCA). The combination of immunochromatography with coagulation-based detection, known as ELISA-ELCA will be accomplished in a user-friendly 'card' format yielding a color-test indication of the presence of drugs at defined cutoff values. The test system will be developed to allow determination of drug levels appropriate to measure intoxication by testing diluted saliva. The appropriate sensitivity will be determined by using human subjects who are regular marijuana users being administered THC in a controlled performance-evaluation protocol. Mouth swabs will be obtained from each subject at the time the performance test, and several hours later when they are administered a sobriety test. For other drugs, saliva levels will be compared with blood and urine levels in rats currently being used to study THC, cocaine and amphetamine intoxication. At the end of this project, we will have developed a new test system which will yield usable cards capable of identifying individuals with saliva levels of drugs of abuse consistent with intoxication and methods for measuring trace levels of drugs to evaluate long-term abuse. PROPOSED COMMERCIAL APPLICATION The detection of drugs of abuse in saliva will have the advantage of a less invasive test system which in the proposed format will not be much more difficult than the current 'breathalyzer' tests used to detect alcohol abuse.